Have you tried rotating your inserts, they may be dull? Before I mount a new round insert I take a Sharpie and draw a line from the bottom of the screw hole, up the bevel and accross the top to the top of the screw hole. This becomes "North". I then mount the insert with North at 12 O'clock, so as I feel the need to rotate I can keep track of how far the insert has been turned. Since I regularly use so much of the the round insert's surface I make only four rotations (North, South, East and West) before I toss the insert. I mark the squarea and diamone inserts in a similar fashion. The ink on the top of the insert can be rubbed off in use, hence the ink on the unexposed underside.I always felt the EWT tools weren't cutting as well.